Generally, a turbocharger has a supercharging structure in which it compresses intake air supplied to an engine using power of exhaust gas, and supplies the compressed intake air to a cylinder to increase intake air charging efficiency and increase an average effective pressure, thereby increasing engine output.
The turbocharger has a structure in which a general compressor and a turbine are disposed on an axis and the turbine is rotated by the power of exhaust gas discharged through an exhaust pipe and rotates the compressor disposed on the axis with the turbine, thereby compressing air introduced through an intake manifold and supplying the compressed air to the cylinder.
During this process, the air compressed by the turbocharger increases in temperature. If the warmed air is supplied to a combustion chamber, an increase ratio of air density is reduced and charging efficiency may be reduced or knocking may occur. To lower the temperature of supercharged air, an intercooler is provided. FIG. 1 is a diagram illustrating an existing intercooler. Referring to FIG. 1, the intake air cooled while passing through the intercooler is maintained at a high density and is cooled to improve combustion power.
Intercoolers are generally classified into an air cooling type and a water cooling type, depending on a cooling method. The air cooling type intercooler has a structure in which it is cooled by cold air passing through a cooling fin integrally formed with the tube while the supercharged air passes through a plurality of tubes. The water cooling type intercooler has a structure in which cooling is accomplished by a cooling channel contacting the tube.
Generally, the air cooling intercooler has good cooling efficiency but has difficulty in achieving stable efficiency due to changes in outdoor temperature, etc. Further, the water cooling type intercooler may maintain stable efficiency, but has a problem in that cooling efficiency is more reduced than that of the air cooling type.